Needle-bar mechanism for sewing-machines.



Patented Nov. 4, |902. A. RUNTKE. Y NEEDLE BAR MEGHANISM FORSEWING MACHINES. (Application led Nov. 26, 1901.) No Modem"4 www?? .FL-1m In vengar Patented Nov. 4, 1902.

' A. Rourke. NEEDLE BAR MECHANISM FR SEWING MACHINES.

(Application filed Nov. 26, 1901.)

3 Sheets-Sheet 2.

I (Nuo Model.)

Mfr M;

No. 712,853. Patented Nov. 4, |902'.

A. RONTKE.

EEDL'E BAR MECHANISM FOB SEWING MACHINES.

(Application filed Nov. 26, 1901.)

(No Model.) f 3 Sheeis-Sheet 3.

UNIT

Starr-3s Arnim OFFICE.

ALBERT RONTKE, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO-THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEV JERSEY.

NEEDLE-BAR MECHANISM FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 712,853, dated November 4, 1902.

' Application filed November 26, 1901. Serial No. 83,769. (No model.) Y

1'0 @ZZ wwm may 007000771# equally well adapted for all multineedle-ma- Be it known that LALBERT RONTKE, a citi-` chines in which a loop-taker or loop-takers zen of the United States, residing at Elizaof any description cooperate each with two or beth, in the county of Union and State of New more needles in forming a seam and that its 5 Jersey, have invented certain new and useadaptation is not limited in its broadest as- 55 ful Improvements in Sewing-Machines, of peet to needle-bar mechanisms, as it may be which the following is a specification, referreadily 'adapted to any other portions of the ence being had therein to the accompanying machine in which two or more parallel or drawings. axially-coincident reciprocating members are Io This invention relates to an improvement required to have relatively differential recip- 6o in that class of multiple,sewing-machines in` rocating movements of equal extent and in which the loop-taker cooperates with two or equal times. more reciprocating needles having coincident The annexed drawings illustrate the invenor parallel axes of motion in the formation of tion as embodied in a twin-needle machine of I5 stitches; and it has for its object to so time the general construction disclosed in the 65 the relative movements of the needles that United States Patent No. 568,702, granted to each is brought independently into operation me September 29, 1896, in which the loop-tak- With the common loop-taker. l-Ieretofore a ing member consists of an oscillating threadsimilar result has been attained in twin-neecarrying looper.

zo dle machines by means of a common needle- Figure l isafront side viewof the machine 7o bar carrying two needles of differentlengths, with the outer portion of the arm partiallyin of which the longer was disposed farther from section to expose the needle-bar-actuating the loop-taker in its forward or loop-seizing mechanism, and Fig. 2 an end'view of the movements. SuchV arrangement had, howsame with the face-plate partially broken 25 ever, the disadvantage of requiring an exaway to expose the same parts. Fig. 3 is a 75 cessive needle-bar movement to afford suf- 'diagrammatic view showing the needle-bar cient dwell of the longer needle beneath the mechanismin itsintermediate position in full cloth-plate to expose its loop to the loop-taker p lines and in'extreme positions in dotted lines. after the latter has taken that of the shorter Fig. 4' is a face View of the needle-bar mech- 5o needle and also to provide clearance for the anism and the stitch-forming devices in the 8o Work above the cloth-plate and beneath the position assumed when the looper has taken longer needle at the upper end of its stroke. the loop of the needle-thread from one needle It is the object of the present invention to and is about taking the loop from the other obviate these defects. needle; and Fig. 5, an elevation of the same 35 The invention therefore consists in mechparts, showing the needle-'bar mechanism in 85 anism whereby each of the needles is' given edge view. Figs.l 6 and 7 are elevational an equal length of movement; but the needle views similar to Figs. 4C and 5, showing the or needles farther fromV the initial loop-seizrelation of the parts when the needles are deing position of the loop-taker receive a dwell scending, the first having passed through the 4o at both ends of their stroke and an accelerlooper-loop and the second being about to 9o ated movementintermediate thereto. By this enter the same. Figs. 8 and 9 are transverse means two or more needles of equal length sections on lines 8 8 and 9 9 in Figs. 4 and 5, may be employed in conjunction with needlerespectively. bars receiving comparatively short recpro- A denotes the Work-plate; B, the bracket- 45 cations of equal length regardless of the gage arm of the machine, said arm having at its 9; of the seam to be produced by said looper and front end the usual head b, affording bearings coperating needles. for the presser-bar c and the main or primary? While the present improvement is designed needle bar d, which is longitudinally grooved more particularly for use in connection with or channeled to receive and guide the shorter 5o twin-needle machines, it is obvious that it is auxiliary or secondary-needle bar e, the axis rco of motion of which is substantially coincident or parallel with that of the primary-needle bar d.

C is the needle-bar-actuating rock-shaft, journaled in the upper part of the arm B and carrying at its front end the crank f, having` the crank pin or stud g, to which is jointed the upright arm 7L of a bell-crank or elbow lever or rocker which is fulcrurned at its elbow or apex upon a pivotal pin or study', carried by a collar 7c, fixed upon the primaryneedle har d. The lateral arm t of the bellcrank or rocker carries a pin or stud Z, jointed 1o one end of a link m, whose other end embraces a pivotal pin o, carried by a lateral lug projecting from a collar p, fixed to the secondary-needle bare, bntem bracing loosely the primary-needle bar d below its fixed collar Each of the needle-bars is provided in its lower end with the usual needle-socket, in which is clamped a needle n by means of a set-screw s, the auxiliary-needle bar having a lateral boss or projection q, to which is attached a band or strap 7', embracing the primary-needle bar and slotted to accommodate its clamp-screw.

The needles are set in their respective bars in such manner that their eyes will he at the same level when at the ends of their'movement and are disposed in a vertical plane transversely of the feed to coperate with a a loop-taker operating in substantially the same plane and herein shown as consisting in an oscillating thread-carrying looper L of well-known form deriving its oscillatory and needle-avoiding lateral movements from the main shaft D.

In the operation of the machine the arm 7l of the bell-crank or rocker serves as a link through which the primary-needle bar d receives the usual reciprocating movement from the actuating-cranky, and the arm t constitutes an offset therefrom, the elevation of which in relation to that of the fnlcrum varies with the" inclination of the arm 7L from the vertical as determined by the position of the actuating-crank, the constantly-changing difference in relative heights of the arm t' and the fulcrumj determining the degree of variation in the heights of the needles in relation to the cloth-plate. Thus by reference to Fig. 3 it will be seen that the arm 7L is vertical in its extreme upper and lower positions and that it becomes inclined to the right in constantly increasing degree until the crank f reaches its intermediate or horizontal position, wherein it attains its maximum inclination, from which position its inclination decreases in similar manner throughout the remainder of its descending movement, the arm 'L' following such motions and through the link m and collar j) causing a corresponding axial movement of the auxiliary-needle bar in relation to the primary-needle bar. The ascent of the crankf to its upper position obviously effects similar variations in the ascent of the needle-bars. It is evident that in the lower portion of the needle-bar movement, which only affects the loop-taking operations of the stitch-forming members, the lateral arm i of the bell-crank or rocker has a dip which constantly diminishes as the crankfdescends below its intermediate position and similarlyincreases during the rising m'otion ot' the crank. `Thus while the maximum advance of the auxiliary needle in relation to the primary needle is gradually compensated for by its slower progress in the lower portion of its descent it enters the looper-loop sufficiently in advance of the primary needle, as indicated in Figs. 6 and 7, to enable the looper to recede at the same time as would be possible in case the primary needle only were employed. In corresponding manner the auxiliary needle lags behind the primary needle in their ascent, as indicated in Figs. 4 and 5, to allow suicient time for the point of the looper to advance from the former to the latter, so as to enable the looper to seize the auxiliary-needle thread loop after having taken the primary-needle thread loop.

By the improvement as above described not only is provision made for a minimum needlebar stroke for multineedle-machines of the class described, but the loop-taking operations are rendered certain, owing to the -dip of the needles being equal in the needle-looptaking positions, and consequently to the equal lengths of thread from the needle-eyes to the cloth-plate from which such loops are formed.

While the proportion and arrangement of parts herein shown and described are considered preferable for reasons heretofore given, it is obvious that they may be Widely varied to suit other conditions and requirements, and the invention is not, therefore, limited to the specific construction, proportion, and arrangement of parts herein set forth. It is evident that resetting the crankfupon its shaft C and correspondingly changing the lengths of the upright arm h and link fm would have the effect of varying the relative positions of the needles at the opposite ends of their stroke, while a change in the relative lengths of the lateral arm t' of the bell-crank or rocker and the actuating-crank fwould produce a corresponding variation in the relative movements of the needles.

It is to be understood that the terms bellcrank, elbow-lever, and rocker as used herein are intended to cover all devices for transmitting and redirecting reciprocating motions, and therefore apply to any members, each of such points being out of line with the fulcrum and the other of said points.

Having thus described my invention, I claim and desire to secure by Letters Patentl. In a sewing-machine, the combination with a plurality of reciprocating members arranged to move in parallel lines, of a twr'A "H armed rocker fulcrumed upon one of s ,1d

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needle-bars and a thread-carryin g looper coperating with the needles of said needle-bars, of means, connected with said needle-bars, for causing the same to reciprocate in the same direction at the same time, but at varying speeds; so that the needles of said needlebars, while starting downward from the same level will be at different levels during certain points of their travel.

3. In a sewing-machine, the combination with a plurality of independently-movable needle-bars and a thread-carrying looper cooperating with the needlesof said needlebars, of means, connected with said needlebars, for causing the same to reciprocate in the same direction at the same time, and to perform movements of equal lengthsgbut at varyingr speeds; so that the needles of said needle-bars, while starting downward from the same level will be at different levels during certain points of their travel.

4. In a sewing-machine, the combination with a plurality of independently-movable needle-bars and a thread-carrying looper cooperating wilh the needles of said needlebars, of an operating mechanism for said needle-bars whereby they will be caused to perform simultaneous reciprocating movements` in the same directions and of equal extent and at equal times, but at dierent speeds during portions of their movements.

5. In a sewing-machine', the combination with a plurality of independently -lnovable needle-bars and a loop-taking device coperating with the needles of said needle-bars, of a two-armed rocker fulcrumed upon one of said needle-bars and bodily movable vertically therewith, an actuating device for said rocker movable in a curved path and connected with one arm of said rocker, the other arm of said rocker, being connected with the other or others of said needle-bars; whereby reciprocating movements of equal length and in equal times, but at differential. speeds, will be imparted to said needle-bars.

6. In a sewing-machine, the combination with two independently-movable needle-bars and a loop-taking device cooperating with the needles of said needle-bars, of a bellcrank or elbow lever fulcrnmed on one of said needle-bars and bodily movable therewith, a rock-shaft having an arm to which one arm of said elbow-lever is jointed, and a link connecting the other arm of said bellcrank or elbow lever with the other of said needle-bars; whereby reciprocating movements of equal length and in equal times, but at differential speeds, will be imparted to said needle-bars.

In testimony whereof I aix my signature in presence of two witnesses.

ALBERT RONTKE.

Witnesses:

HENRY J. MILLER, HENRY A. KORNEMANN. 

